How to seal gap between garage brick wall and ceiling?

[bkz]

There's a small gap running along & between our garage brick wall and ceiling which allows rain to fall through from the roof space. We're looking to seal up this gap somehow. Is there a way to do this and that’s waterproof?

I have attached photos and there seems to be some painted / colored sections on the brick edge, potentially old owner tried to seal this area previously? Or what is this?

 

 

[bkz]

Possibly that’s the other option I was thinking of, I’ll sus it out after the holidays & report back.

thank you